How can backup contact from iPhone 4 to?

How can backup contact from iPhone 4 to?

From your sim card

To where? If you we're going to say computer, just connect your phone to your computer and if iTunes is installed, it will open automatically. After that in your iPhone page on iTunes, there will be a "backup iPhone" button. Click on it and wait for it to backup you iPhone. It will backup contacts, settings, calendar, and everything else except your apps